diff options
author | Dan Williams <dan.j.williams@intel.com> | 2015-06-09 21:13:37 +0300 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2015-06-25 04:24:10 +0300 |
commit | 18da2c9ee41a036bf470dbad73c18a815725d36e (patch) | |
tree | c69bb8f44dcb1df4c7579184c3051e5b51729d87 /drivers/nvdimm | |
parent | 3d88002e4a7bd40f355550284c6cd140e6fe29dc (diff) | |
download | linux-18da2c9ee41a036bf470dbad73c18a815725d36e.tar.xz |
libnvdimm, pmem: move pmem to drivers/nvdimm/
Prepare the pmem driver to consume PMEM namespaces emitted by regions of
an nvdimm_bus instance. No functional change.
Acked-by: Christoph Hellwig <hch@lst.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/nvdimm')
-rw-r--r-- | drivers/nvdimm/Kconfig | 23 | ||||
-rw-r--r-- | drivers/nvdimm/Makefile | 3 | ||||
-rw-r--r-- | drivers/nvdimm/pmem.c | 262 |
3 files changed, 287 insertions, 1 deletions
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig index 92933551f846..07a29113b870 100644 --- a/drivers/nvdimm/Kconfig +++ b/drivers/nvdimm/Kconfig @@ -1,4 +1,4 @@ -config LIBNVDIMM +menuconfig LIBNVDIMM tristate "NVDIMM (Non-Volatile Memory Device) Support" depends on PHYS_ADDR_T_64BIT depends on BLK_DEV @@ -13,3 +13,24 @@ config LIBNVDIMM CONFIG_DAX). A BLK namespace refers to an NVDIMM control region which exposes an mmio register set for windowed access mode to non-volatile memory. + +if LIBNVDIMM + +config BLK_DEV_PMEM + tristate "PMEM: Persistent memory block device support" + default LIBNVDIMM + depends on HAS_IOMEM + help + Memory ranges for PMEM are described by either an NFIT + (NVDIMM Firmware Interface Table, see CONFIG_NFIT_ACPI), a + non-standard OEM-specific E820 memory type (type-12, see + CONFIG_X86_PMEM_LEGACY), or it is manually specified by the + 'memmap=nn[KMG]!ss[KMG]' kernel command line (see + Documentation/kernel-parameters.txt). This driver converts + these persistent memory ranges into block devices that are + capable of DAX (direct-access) file system mappings. See + Documentation/nvdimm/nvdimm.txt for more details. + + Say Y if you want to use an NVDIMM + +endif diff --git a/drivers/nvdimm/Makefile b/drivers/nvdimm/Makefile index af5e2760ddbd..4d2a27f52faa 100644 --- a/drivers/nvdimm/Makefile +++ b/drivers/nvdimm/Makefile @@ -1,4 +1,7 @@ obj-$(CONFIG_LIBNVDIMM) += libnvdimm.o +obj-$(CONFIG_BLK_DEV_PMEM) += nd_pmem.o + +nd_pmem-y := pmem.o libnvdimm-y := core.o libnvdimm-y += bus.o diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c new file mode 100644 index 000000000000..eabf4a8d0085 --- /dev/null +++ b/drivers/nvdimm/pmem.c @@ -0,0 +1,262 @@ +/* + * Persistent Memory Driver + * + * Copyright (c) 2014, Intel Corporation. + * Copyright (c) 2015, Christoph Hellwig <hch@lst.de>. + * Copyright (c) 2015, Boaz Harrosh <boaz@plexistor.com>. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + */ + +#include <asm/cacheflush.h> +#include <linux/blkdev.h> +#include <linux/hdreg.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/slab.h> + +#define PMEM_MINORS 16 + +struct pmem_device { + struct request_queue *pmem_queue; + struct gendisk *pmem_disk; + + /* One contiguous memory region per device */ + phys_addr_t phys_addr; + void *virt_addr; + size_t size; +}; + +static int pmem_major; +static atomic_t pmem_index; + +static void pmem_do_bvec(struct pmem_device *pmem, struct page *page, + unsigned int len, unsigned int off, int rw, + sector_t sector) +{ + void *mem = kmap_atomic(page); + size_t pmem_off = sector << 9; + + if (rw == READ) { + memcpy(mem + off, pmem->virt_addr + pmem_off, len); + flush_dcache_page(page); + } else { + flush_dcache_page(page); + memcpy(pmem->virt_addr + pmem_off, mem + off, len); + } + + kunmap_atomic(mem); +} + +static void pmem_make_request(struct request_queue *q, struct bio *bio) +{ + struct block_device *bdev = bio->bi_bdev; + struct pmem_device *pmem = bdev->bd_disk->private_data; + int rw; + struct bio_vec bvec; + sector_t sector; + struct bvec_iter iter; + int err = 0; + + if (bio_end_sector(bio) > get_capacity(bdev->bd_disk)) { + err = -EIO; + goto out; + } + + BUG_ON(bio->bi_rw & REQ_DISCARD); + + rw = bio_data_dir(bio); + sector = bio->bi_iter.bi_sector; + bio_for_each_segment(bvec, bio, iter) { + pmem_do_bvec(pmem, bvec.bv_page, bvec.bv_len, bvec.bv_offset, + rw, sector); + sector += bvec.bv_len >> 9; + } + +out: + bio_endio(bio, err); +} + +static int pmem_rw_page(struct block_device *bdev, sector_t sector, + struct page *page, int rw) +{ + struct pmem_device *pmem = bdev->bd_disk->private_data; + + pmem_do_bvec(pmem, page, PAGE_CACHE_SIZE, 0, rw, sector); + page_endio(page, rw & WRITE, 0); + + return 0; +} + +static long pmem_direct_access(struct block_device *bdev, sector_t sector, + void **kaddr, unsigned long *pfn, long size) +{ + struct pmem_device *pmem = bdev->bd_disk->private_data; + size_t offset = sector << 9; + + if (!pmem) + return -ENODEV; + + *kaddr = pmem->virt_addr + offset; + *pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT; + + return pmem->size - offset; +} + +static const struct block_device_operations pmem_fops = { + .owner = THIS_MODULE, + .rw_page = pmem_rw_page, + .direct_access = pmem_direct_access, +}; + +static struct pmem_device *pmem_alloc(struct device *dev, struct resource *res) +{ + struct pmem_device *pmem; + struct gendisk *disk; + int idx, err; + + err = -ENOMEM; + pmem = kzalloc(sizeof(*pmem), GFP_KERNEL); + if (!pmem) + goto out; + + pmem->phys_addr = res->start; + pmem->size = resource_size(res); + + err = -EINVAL; + if (!request_mem_region(pmem->phys_addr, pmem->size, "pmem")) { + dev_warn(dev, "could not reserve region [0x%pa:0x%zx]\n", &pmem->phys_addr, pmem->size); + goto out_free_dev; + } + + /* + * Map the memory as non-cachable, as we can't write back the contents + * of the CPU caches in case of a crash. + */ + err = -ENOMEM; + pmem->virt_addr = ioremap_nocache(pmem->phys_addr, pmem->size); + if (!pmem->virt_addr) + goto out_release_region; + + pmem->pmem_queue = blk_alloc_queue(GFP_KERNEL); + if (!pmem->pmem_queue) + goto out_unmap; + + blk_queue_make_request(pmem->pmem_queue, pmem_make_request); + blk_queue_max_hw_sectors(pmem->pmem_queue, 1024); + blk_queue_bounce_limit(pmem->pmem_queue, BLK_BOUNCE_ANY); + + disk = alloc_disk(PMEM_MINORS); + if (!disk) + goto out_free_queue; + + idx = atomic_inc_return(&pmem_index) - 1; + + disk->major = pmem_major; + disk->first_minor = PMEM_MINORS * idx; + disk->fops = &pmem_fops; + disk->private_data = pmem; + disk->queue = pmem->pmem_queue; + disk->flags = GENHD_FL_EXT_DEVT; + sprintf(disk->disk_name, "pmem%d", idx); + disk->driverfs_dev = dev; + set_capacity(disk, pmem->size >> 9); + pmem->pmem_disk = disk; + + add_disk(disk); + + return pmem; + +out_free_queue: + blk_cleanup_queue(pmem->pmem_queue); +out_unmap: + iounmap(pmem->virt_addr); +out_release_region: + release_mem_region(pmem->phys_addr, pmem->size); +out_free_dev: + kfree(pmem); +out: + return ERR_PTR(err); +} + +static void pmem_free(struct pmem_device *pmem) +{ + del_gendisk(pmem->pmem_disk); + put_disk(pmem->pmem_disk); + blk_cleanup_queue(pmem->pmem_queue); + iounmap(pmem->virt_addr); + release_mem_region(pmem->phys_addr, pmem->size); + kfree(pmem); +} + +static int pmem_probe(struct platform_device *pdev) +{ + struct pmem_device *pmem; + struct resource *res; + + if (WARN_ON(pdev->num_resources > 1)) + return -ENXIO; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENXIO; + + pmem = pmem_alloc(&pdev->dev, res); + if (IS_ERR(pmem)) + return PTR_ERR(pmem); + + platform_set_drvdata(pdev, pmem); + + return 0; +} + +static int pmem_remove(struct platform_device *pdev) +{ + struct pmem_device *pmem = platform_get_drvdata(pdev); + + pmem_free(pmem); + return 0; +} + +static struct platform_driver pmem_driver = { + .probe = pmem_probe, + .remove = pmem_remove, + .driver = { + .owner = THIS_MODULE, + .name = "pmem", + }, +}; + +static int __init pmem_init(void) +{ + int error; + + pmem_major = register_blkdev(0, "pmem"); + if (pmem_major < 0) + return pmem_major; + + error = platform_driver_register(&pmem_driver); + if (error) + unregister_blkdev(pmem_major, "pmem"); + return error; +} +module_init(pmem_init); + +static void pmem_exit(void) +{ + platform_driver_unregister(&pmem_driver); + unregister_blkdev(pmem_major, "pmem"); +} +module_exit(pmem_exit); + +MODULE_AUTHOR("Ross Zwisler <ross.zwisler@linux.intel.com>"); +MODULE_LICENSE("GPL v2"); |